Input devices, such as optical computer mice, trackballs, joysticks, and touch pads, are commonly used for interfacing with host data processing systems, such as personal computers, workstations, entertainment systems, and game consoles. Conventional input devices typically operate in one of two communication protocols or modes, either a wired protocol in which the input device communicates with the host system via a cable, or a wireless protocol in which the device communicates via an infrared (IR) or radio link. The wired protocol is inconvenient in that the cable is cumbersome and limits the movement of the input device. The wireless protocol allows for the omission of the cable, but requires batteries to supply power for the device, which can result in drawbacks. For example, replacement or recharging of the batteries typically results in the device not being useable for a period.